Question

For cell reaction: \[{\rm{Zn}} + {\rm{C}}{{\rm{u}}^{2 + }} \to {\rm{Z}}{{\rm{n}}^{{\rm{2 + }}}} + {\rm{Cu}}\] , cell representation is:
A. Zn|\[{\rm{Z}}{{\rm{n}}^{{\rm{2 + }}}}\]||\[{\rm{C}}{{\rm{u}}^{{\rm{2 + }}}}\]|Cu
B. Cu|\[{\rm{C}}{{\rm{u}}^{{\rm{2 + }}}}\]||\[{\rm{Z}}{{\rm{n}}^{{\rm{2 + }}}}\]|Zn
C. Cu|\[{\rm{Z}}{{\rm{n}}^{{\rm{2 + }}}}\]||Zn|\[{\rm{C}}{{\rm{u}}^{{\rm{2 + }}}}\]
D. \[{\rm{C}}{{\rm{u}}^{{\rm{2 + }}}}\]|Zn||\[{\rm{Z}}{{\rm{n}}^{{\rm{2 + }}}}\]|Cu

Answer 1

Hint: There are two electrodes namely cathode and anode that consist of an electrochemical cell. These electrodes are dipped in a solution called electrolytes and two half cells are formed. When these two half cells are combined it leads to the formation of a cell.

Complete Step by Step Solution:
Let's discuss the rules of representation of cells.
1) In a galvanic cell representation, anode, where oxidation occurs, is to be written on the left and cathode is to be written on the right-hand side.
2) The representation of the anode is done by writing the solid phase of the metal and then the cation of the metal. And the representation of the cathode is done by first writing the cation and then the metal.
3) The separation of metal and the cation is done by using a vertical line.
4) The salt bridge that does the function of the separation of two half cells is represented by two vertical lines.

Here, the given electrochemical cell consists of electrodes of copper and zinc.
So, the oxidation reaction that occurs at the anode is,
\[{\rm{Zn}} \to {\rm{Z}}{{\rm{n}}^{2 + }} + 2{e^ - }\]
And the cathodic reaction is,
\[{\rm{C}}{{\rm{u}}^{{\rm{2 + }}}} + {\rm{2}}{{\rm{e}}^ - } \to {\rm{Cu}}\]

Therefore, the correct cell representation is Zn|\[{\rm{Z}}{{\rm{n}}^{{\rm{2 + }}}}\]||\[{\rm{C}}{{\rm{u}}^{{\rm{2 + }}}}\]|Cu.
Hence, option A is right.

Note: A process in which the passing of electricity occurs through the electrolyte and a chemical reaction occurs is termed electrolysis. And a device that generates electricity through electrolysis is called galvanic cell or electrochemical cell